JP2013197474A - Substrate processing method, semiconductor device manufacturing method and substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing method, a semiconductor device manufacturing method, and a substrate processing apparatus which can uniformly deposit a plurality of substrates and reliably remove by-products in an exhaust pipe when performing SiC epitaxial film growth under a high temperature condition thereby to improve productivity and safety.SOLUTION: A substrate processing method comprises: a boat loading process of carrying in a plurality of substrates while being held by a boat into a reaction chamber; a gas supply process of supplying a gas to the substrates; an exhaust process of exhausting the gas supplied in the gas supply process from an exhaust pipe; and a cleaning gas supply process of supplying a cleaning gas for cleaning inside the exhaust pipe to a cleaning gas flow path in the exhaust pipe.

Description

The present invention relates to a substrate processing apparatus for processing a substrate, a method for manufacturing a semiconductor device, and a method for manufacturing a substrate, in particular, a substrate processing apparatus and a semiconductor including a step of forming a silicon carbide (hereinafter referred to as SiC) epitaxial film on a substrate. The present invention relates to an apparatus manufacturing method and a substrate manufacturing method.

SiC is attracting particular attention as a power device element material because of its wide energy band gap, high withstand voltage, and high thermal conductivity compared to silicon (hereinafter referred to as Si). On the other hand, it is known that SiC does not have a liquid phase under normal pressure, and the impurity diffusion coefficient is small, so that it is difficult to produce a crystal substrate or a semiconductor device compared to Si. For example, since the epitaxial film formation temperature of SiC is as high as 1500 ° C. to 1800 ° C. compared to the epitaxial film formation temperature of Si of 900 ° C. to 1200 ° C., the substrate processing apparatus for forming the SiC epitaxial film has a heat resistant structure. In addition, it is necessary to devise technical measures to suppress decomposition of raw material gas. In addition, since the film forming temperature is high, it is necessary to devise technical measures for the heat-resistant structure and the removal of by-products in the exhaust system after the film forming process. Furthermore, in a substrate processing apparatus for forming a SiC epitaxial film, since film formation using two elements of Si and C (hereinafter also referred to as carbon) is performed, it is possible to ensure film thickness and composition uniformity and to achieve a doping level. For the control, a device that does not exist in the substrate processing apparatus for forming the Si film is required.

When a device is manufactured using SiC, a wafer in which a SiC epitaxial film is formed on a SiC substrate is used. As an example of a SiC epitaxial growth apparatus for forming a SiC epitaxial film on this SiC substrate, there is Patent Document 1.

JP 2011-388A

In view of such circumstances, the present invention can uniformly form a plurality of substrates in SiC epitaxial film growth performed under high temperature conditions, and can reliably remove by-products in the exhaust pipe to improve productivity. The present invention provides a substrate processing apparatus, a semiconductor device manufacturing method, and a substrate processing method capable of improving safety.

According to one aspect of the present invention, a boat loading step of loading a plurality of substrates into a reaction chamber while being held in a boat, a gas supply step of supplying a gas to the substrate, and the gas supply step There is provided a substrate processing method comprising: an exhaust process for exhausting gas from an exhaust pipe; and a cleaning gas supply process for supplying a cleaning gas to a cleaning gas flow path in the exhaust pipe in order to clean the inside of the exhaust pipe. .

Further, according to another aspect of the present invention, a boat loading step of loading a plurality of substrates into a reaction chamber while being held in a boat, a gas supply step of supplying gas to the substrates, and the gas supply step An exhaust process for exhausting the gas supplied from the exhaust pipe and a cleaning gas supply process for supplying a cleaning gas to a cleaning gas flow path in the exhaust pipe in order to clean the inside of the exhaust pipe A manufacturing method is provided.

Furthermore, according to one embodiment of the present invention, the reaction chamber for processing a plurality of substrates, a heating unit provided so as to surround the reaction chamber, and the plurality of substrates are held in the reaction chamber while being held. A boat, a gas supply unit installed in the reaction chamber, an exhaust unit for exhausting the gas supplied into the reaction chamber through an exhaust pipe, and a gas provided in the exhaust unit for cleaning the exhaust unit There is provided a substrate processing apparatus having a cleaning gas supply unit, a control unit for controlling a flow rate of gas supplied from the gas supply unit, and a flow rate of cleaning gas supplied from the cleaning gas supply unit.

According to the present invention, it is possible to provide a substrate processing method, a semiconductor device manufacturing method, and a substrate processing apparatus that can improve productivity.

1 is a perspective view of a semiconductor manufacturing apparatus to which the present invention is applied. It is side surface sectional drawing of the processing furnace to which this invention is applied. It is a plane sectional view of a processing furnace to which the present invention is applied. It is a figure explaining the gas supply unit of the semiconductor manufacturing apparatus with which this invention is applied. It is a block diagram which shows the control structure of the semiconductor manufacturing apparatus with which this invention is applied. It is a schematic sectional drawing of the processing furnace of the semiconductor manufacturing apparatus with which this invention is applied, and its peripheral structure. It is side surface sectional drawing of the exhaust piping of the semiconductor manufacturing apparatus with which this invention is applied. It is an analysis figure of the cleaning gas flow in the exhaust piping of the semiconductor manufacturing device to which the present invention is applied. It is the figure which showed the short tube nozzle installed in the exhaust pipe of the semiconductor manufacturing apparatus with which this invention is applied. It is an analysis figure at the time of supplying predetermined amount of cleaning gas in the exhaust piping to which this invention is applied using a short tube nozzle. It is a figure which shows the quartz wall installed in the exhaust pipe of the semiconductor manufacturing apparatus with which this invention is applied. It is sectional drawing of the exhaust piping to which this invention is applied, and a quartz wall. It is an analysis figure at the time of supplying a predetermined amount of cleaning gas using the quartz wall in the exhaust pipe to which the present invention is applied. It is an analysis figure of the side surface of an exhaust pipe which analyzed about the amount of supply when a quartz wall is provided in the exhaust pipe to which the present invention is applied and cleaning gas is supplied.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a so-called batch type vertical SiC epitaxial growth apparatus in which SiC wafers are arranged in the height direction in a SiC epitaxial growth apparatus which is an example of a substrate processing apparatus will be described. In addition, by setting it as a batch type vertical SiC epitaxial growth apparatus, the number of the SiC wafers which can be processed at once increases and a throughput improves.

<Overall configuration>
First, referring to FIG. 1, a substrate processing apparatus for forming a SiC epitaxial film according to the first embodiment of the present invention, and a substrate for forming a SiC epitaxial film which is one of semiconductor device manufacturing steps. The manufacturing method will be described.

A semiconductor manufacturing apparatus 10 as a substrate processing apparatus (film forming apparatus) is a batch type vertical heat treatment apparatus, and includes a housing 12 in which a main part is arranged. In the semiconductor manufacturing apparatus 10, a hoop (hereinafter referred to as a pod) 16 is used as a wafer carrier as a substrate container for storing a wafer 14 (see FIG. 2) as a substrate made of, for example, SiC. A pod stage 18 is disposed on the front side of the housing 12, and the pod 16 is conveyed to the pod stage 18. For example, 25 wafers 14 are stored in the pod 16 and set on the pod stage 18 with the lid closed.

A pod transfer device 20 is disposed in a front face of the housing 12 and at a position facing the pod stage 18. A pod storage shelf 22, a pod opener 24, and a substrate number detector 26 are disposed in the vicinity of the pod transfer device 20. The pod storage shelf 22 is disposed above the pod opener 24 and is configured to hold a plurality of pods 16 mounted thereon. The substrate number detector 26 is disposed adjacent to the pod opener 24, and the pod transfer device 20 transfers the pod 16 among the pod stage 18, the pod storage shelf 22, and the pod opener 24. The pod opener 24 opens the lid of the pod 16, and the substrate number detector 26 detects the number of wafers 14 in the pod 16 with the lid opened.

A substrate transfer machine 28 and a boat 30 as a substrate holder are disposed in the housing 12. The substrate transfer machine 28 has an arm (tweezer) 32, and has a structure that can be moved up and down and rotated by a driving means (not shown). The arm 32 can take out, for example, five wafers 14. By moving the arm 32, the wafer 14 is transferred between the pod 16 and the boat 30 placed at the position of the pod opener 24.

The boat 30 is made of a heat-resistant material such as carbon graphite or SiC, for example, and a plurality of wafers 14 are arranged in a horizontal posture and aligned with their centers aligned, and are stacked and held in the vertical direction. It is configured. Note that a boat heat insulating portion 34 is disposed as a disk-shaped heat insulating member made of a heat resistant material such as quartz or SiC at the lower portion of the boat 30, and heat from the heated body 48 to be described later is processed. It is comprised so that it may become difficult to be transmitted to the downward side of the furnace 40 (refer FIG. 2).

The processing furnace 40 is disposed in the upper part on the back side in the housing 12. The boat 30 loaded with a plurality of wafers 14 is loaded into the processing furnace 40 and subjected to heat treatment.

<Processing furnace configuration>
Next, referring to FIGS. 2, 3, and 4, the processing furnace 40 of the semiconductor manufacturing apparatus 10 for forming a SiC epitaxial film will be described. The processing furnace 40 is provided with a first gas supply nozzle 60 having a first gas supply port 68, a second gas supply nozzle 70 having a second gas supply port 72, and a first gas exhaust port 90. It is done. In addition, a third gas supply port 360 and a second gas exhaust port 390 for supplying an inert gas are shown.

The processing furnace 40 is made of a heat resistant material such as quartz or SiC, and includes a reaction tube 42 formed in a cylindrical shape having a closed upper end and an opened lower end. Below the reaction tube 42, a manifold 36 is disposed concentrically with the reaction tube 42. The manifold 36 is made of, for example, stainless steel and is formed in a cylindrical shape with an upper end and a lower end opened. The manifold 36 is provided so as to support the reaction tube 42 vertically. An O-ring (not shown) as a seal member is provided between the manifold 36 and the reaction tube 42. Since the manifold 36 is supported by a holding body (not shown), the reaction tube 42 is installed vertically. A reaction vessel is formed by the reaction tube 42 and the manifold 36.

The processing furnace 40 includes a derivative 48 formed in a cylindrical shape with an upper end closed and a lower end opened, and an induction coil 50 as a magnetic field generation unit. A reaction chamber 44 is formed in a cylindrical hollow portion of the to-be-derivatized 48, and is configured to be able to store a boat 30 holding a wafer 14 as a substrate made of SiC or the like. Further, as shown in the lower frame of FIG. 2, the wafer 14 is held by the boat 30 in a state where the wafer 14 is held by the annular lower wafer holder 15b and the upper surface is covered by the disk-like upper wafer holder 15a. Good. Thereby, the wafer 14 can be protected from particles falling from the upper part of the wafer, and film formation on the back surface side with respect to the film formation surface (lower surface of the wafer 14) can be suppressed. Further, the film forming surface can be separated from the boat column of the wafer holder 15, and the influence of the boat column can be reduced. The boat 30 is configured to hold the wafers 14 held by the wafer holder 15 so as to be aligned in the vertical direction in a horizontal posture and with the centers aligned. The derivative 48 is heated by a magnetic field generated by an induction coil 50 provided outside the reaction tube 42, and the reaction chamber 44 is heated when the derivative 48 generates heat. It is like.

In the vicinity of the derivative 48, a temperature sensor (not shown) is provided as a temperature detector that detects the temperature in the reaction chamber 44. The induction coil 50 and the temperature sensor are electrically connected to the temperature control unit 52, and the inside of the reaction chamber 44 is adjusted by adjusting the degree of energization to the induction coil 50 based on the temperature information detected by the temperature sensor. The temperature is controlled at a predetermined timing so as to obtain a desired temperature distribution (see FIG. 5).

Preferably, in the reaction chamber 44, between the first and second gas supply nozzles 60, 70 and the first gas exhaust port 90, and between the heated object 48 and the wafer 14. In the meantime, a structure 300 extending in the vertical direction and having an arc-shaped cross section is preferably provided in the reaction chamber 44 so as to fill the space between the heated object 48 and the wafer 14. For example, as shown in FIG. 3, by providing the structures 300 at the opposing positions, the gas supplied from the first and second gas supply nozzles 60 and 70 is transferred along the inner wall of the derivative 48 to the wafer. Bypassing 14 can be prevented. When the structure 300 is preferably made of a heat insulating material, carbon felt or the like, heat resistance and generation of particles can be suppressed.

Between the reaction tube 42 and the to-be-derivatized 48, a heat insulating material 54 made of, for example, a carbon felt that is not easily dielectric is provided. By providing the heat insulating material 54, the heat of the to-be-derivatized 48 is changed to the reaction tube 42 or Can suppress the transmission to the outside of the reaction tube 42.

In addition, an outer heat insulating wall 55 having, for example, a water cooling structure is provided outside the induction coil 50 so as to suppress the heat in the reaction chamber 44 from being transmitted to the outside so as to surround the reaction chamber 44. Further, a magnetic seal 58 for preventing the magnetic field generated by the induction coil 50 from leaking outside is provided outside the outer heat insulating wall 55.

As shown in FIG. 2, a first gas supply nozzle 60 provided with at least one first gas supply port 68 is installed between the derivative 48 and the wafer 14. Further, a second gas supply nozzle 70 provided with at least one second gas supply port 72 is provided at a location different from the first gas supply nozzle 60 between the derivative 48 and the wafer 14. . Similarly, the first gas exhaust port 90 is also disposed between the heated object 48 and the wafer 14. In addition, a third gas supply port 360 and a second gas exhaust port 390 are disposed between the reaction tube 42 and the heat insulating material 54. The gas types supplied from the first gas supply nozzle 60 and the second gas supply nozzle 70 will be described later.

The first gas supply port 68 and the first gas supply nozzle 60 are made of, for example, carbon graphite and are provided in the reaction chamber 44. The first gas supply nozzle 60 is attached to the manifold 36 so as to penetrate the manifold 36. The first gas supply nozzle 60 is connected to the gas supply unit 200 via the first gas line 222.

The second gas supply port 72 and the second gas supply nozzle 70 are made of, for example, carbon graphite and are provided in the reaction chamber 44. The second gas supply nozzle 70 is attached to the manifold 36 so as to penetrate the manifold 36. Further, the second gas supply nozzle 70 is connected to the gas supply unit 200 via the second gas line 260.

Further, in the first gas supply nozzle 60 and the second gas supply nozzle 70, one first gas supply port 68 and one second gas supply port 72 may be provided in the arrangement region of the substrate. Alternatively, it may be provided for every predetermined number of wafers 14.

<Exhaust system>
As shown in FIG. 2, a first gas exhaust port 90 is provided below the boat 30, and a gas exhaust pipe 230 connected to the first gas exhaust port 90 is provided in the manifold 36 so as to pass therethrough. ing. On the downstream side of the gas exhaust pipe 230, a pressure sensor (not shown) as a pressure detector and an APC (Auto) as a pressure regulator are provided.
A vacuum exhaust device 220 such as a vacuum pump is connected via a pressure controller (Valve) 214. A pressure control unit 98 is electrically connected to the pressure sensor and the APC valve 214, and the pressure control unit 98 adjusts the opening degree of the APC valve 214 based on the pressure detected by the pressure sensor, thereby processing furnace. Control is performed at a predetermined timing so that the pressure in 40 becomes a predetermined pressure (see FIG. 5).

As described above, the gas supplied from the first gas supply port 68 and the second gas supply port 72 flows in parallel to the wafer 14 made of Si or SiC, and is exhausted from the first gas exhaust port 90. Therefore, the entire wafer 14 is exposed to the gas efficiently and uniformly.

A boat heat insulating portion 34A is provided under the boat 30 so that the manifold 36 and the like are not heated by the radiant heat from the reaction chamber. Further, in the present embodiment, heat exchange is performed to reduce the temperature of the deposition gas by performing heat exchange with the deposition gas so that the deposition gas heated in the reaction chamber does not reach the manifold 36 or the like at a high temperature. Is provided. Specifically, the boat heat insulating portion 34A has a hollow cylindrical shape, and the film forming gas is exhausted along the side surface. Thus, by making the boat heat insulating part 34A cylindrical, the contact area with the film forming gas exhausted is increased, and the efficiency of heat exchange is improved. Moreover, the 1st heat exchange part 34B and the 2nd heat exchange part 34C provided in the lower part of the gas supply nozzle 60 (70) are provided so that the said boat heat insulation part 34A may be enclosed. The first heat exchange unit 34B and the second heat exchange unit 34C are arranged so as to have a gap with the boat heat insulating unit 34A, and the flow of the film forming gas in the reaction chamber flows through the flow path of the film forming gas to be exhausted. It is narrower than the road. Thereby, since the film forming gas is exhausted through the narrow flow path, the efficiency of heat exchange is further improved.

As shown in FIG. 3, the third gas supply port 360 is disposed between the reaction tube 42 and the heat insulating material 54 and attached so as to penetrate the manifold 36. Further, the second gas exhaust port 390 is disposed between the reaction tube 42 and the heat insulating material 54 so as to face the third gas supply port 360, and the second gas exhaust port 390 is a gas It is connected to the exhaust pipe 230. The third gas supply port 360 is formed in a third gas line 240 that penetrates the manifold 36, and the third gas line is connected to the gas supply unit 200. As shown in FIG. 4, the third gas line is connected to a gas supply source 210f via a valve 212f and an MFC 211f. For example, a rare gas Ar gas is supplied as an inert gas from the gas supply source 210f, and a gas contributing to the growth of the SiC epitaxial film is prevented from entering between the reaction tube 42 and the heat insulating material 54. It is possible to prevent unnecessary products from adhering to the inner wall of 42 or the outer wall of the heat insulating material 54.

Further, the inert gas supplied between the reaction tube 42 and the heat insulating material 54 is exhausted from the vacuum exhaust device 220 via the APC valve 214 on the downstream side of the gas exhaust tube 230 from the second gas exhaust port 390. Is done.

Here, the exhaust pipe 230 will be described in more detail with reference to FIG. As shown in FIG. 7, the exhaust pipe 230 has a flange water cooling unit 702, and removes by-products such as a chlorosilane polymer (for example, SiCl2) generated by cooling the exhaust gas by the flange water cooling unit 702. A cleaning gas supply unit 701 is provided to supply exhaust pipe cleaning gas.

  At this time, by-products such as silane chloride polymer produced by cooling the exhaust gas react with moisture in the atmosphere when exposed to the atmosphere, and may be flammable or explosive. Therefore, it is important that the cleaning gas flows uniformly in the exhaust pipe and the by-products are uniformly removed.

FIG. 8 shows the analysis of the distribution of the cleaning gas when Ar is allowed to flow at a constant flow rate (eg, 5 L) under an arbitrary pressure (eg, 2000 Pa). For example, when the flow rate of the cleaning gas ClF3 is used as 750 cc as shown in FIG. 8A, the gas mainly cleans the broken line area A on the opposite side of the surface where the cleaning gas supply unit 701 is installed. When the flow rate of the cleaning gas ClF3 is set to 100 cc as shown in FIG. 8C, the gas is pushed by the mainstream Ar to clean much of the broken line area C which is the surface on which the cleaning gas supply unit 701 is installed. Will be. Further, if the flow rate of the cleaning gas ClF3 is set to 375 cc, which is about the middle flow rate of FIGS. 8A and 8C, as shown in FIG. 8B, the cleaning gas hardly reaches the pipe surface, and the broken line As in the region B, the cleaning is not so much.

  Therefore, as a method for uniformly cleaning the inner surface of the exhaust pipe, for example, a means for providing a short pipe nozzle to be described later in the cleaning gas supply unit 701 or a means for providing a quartz wall to be described later in the vicinity of the gas outlet of the cleaning gas supply nozzle 701. Conceivable.

  Next, a cleaning method in which the short tube nozzle 901 is installed in the cleaning gas supply unit 701 will be described in detail with reference to FIGS. 9 and 10.

  FIG. 9A is a view showing a state in which the short pipe nozzle 901 is installed in the exhaust pipe. For example, as shown in FIG. 9C, four locations are provided at intervals of approximately 90 degrees in the circumferential direction. A short pipe nozzle 901 provided with a cleaning gas jet outlet is installed upstream of the exhaust pipe. As shown in FIG. 9B, the short tube nozzle 901 has a hollow cylindrical shape, and is provided with a cleaning gas ejection port at least at one place, and is fitted or screwed into the cleaning gas supply unit 701. It is provided to do. Here, in FIG. 9A, the short pipe nozzle is provided only at one place, but it may be provided at a plurality of places together with the cleaning gas supply unit 701, and further, the cleaning gas provided at the short pipe nozzle. Needless to say, the jet outlets may be provided at a plurality of locations at intervals different from each other, not at intervals of about 90 degrees.

  FIG. 10 shows a predetermined Ar gas flow rate (for example, 5 L) at a predetermined pressure (for example, 2000 Pa) and a predetermined flow rate of cleaning gas (for example, ClF3) in the exhaust pipe using the short tube nozzle 901 in a state where the predetermined temperature is reached. It is the drawing which analyzed about the case where it supplied.

  For example, when the inside of the exhaust pipe is cleaned with the supply amount of the cleaning gas as 100 cc as shown in FIG. 10C, the cleaning gas flow rate is smaller than that in FIG. 8C when the short pipe nozzle 901 is not used. Nevertheless, it can be confirmed that the gas is supplied in a wide range as in the region F. Similarly, when the cleaning gas supply amount is 300 cc as shown in FIG. 10B, the gas is supplied to the entire exhaust pipe, and particularly in the area E around the flange water cooling unit 702. It can be confirmed that the gas can be supplied substantially uniformly. Further, as shown in FIG. 10 (a), when the cleaning gas supply amount is 1000 cc, it can be confirmed that the entire exhaust pipe can be cleaned substantially uniformly as in the region D.

  Next, the case where a hollow cylindrical quartz wall is provided from the vicinity of the gas outlet of the cleaning gas supply unit 701 will be described with reference to FIGS. 11, 12, 13, and 14. FIG. 11A shows the exhaust pipe when the quartz wall 1101 is installed in the exhaust pipe so that a cleaning gas flow path different from the exhaust gas exhaust flow path is provided in the exhaust pipe. As shown in FIG. 11B, the quartz wall 1101 has a hollow cylindrical shape, and is provided so that its outermost diameter is smaller than the inner diameter of the exhaust pipe 230.

  FIG. 12A is a cross-sectional view of the exhaust pipe 230 and the quartz wall 1101 showing the gas flow when the quartz wall 1101 is provided in the exhaust pipe 230, and FIG. 12B is the exhaust pipe 230 and the quartz wall 1101. FIG.

  The cleaning gas supplied from the cleaning gas supply unit 701 into the exhaust pipe 230 flows along the inner surface of the exhaust pipe 230 by the quartz wall 1101 provided in the vicinity of the supply unit outlet as shown in FIG. As a result, the inner surface of the exhaust pipe can be sufficiently cleaned, and the by-product can be reliably removed. Here, as shown in FIG. 12B, the quartz wall 1101 is provided with a step so as to provide a cleaning gas flow path in the vicinity of the cleaning gas supply port, but this step can be changed as appropriate. Needless to say.

  In FIG. 13, a quartz wall 1101 is provided in the exhaust pipe 230, and a cleaning gas (eg, ClF 3) is supplied into the exhaust pipe at a predetermined pressure (eg, 2000 Pa), a predetermined Ar gas flow rate (eg, 5 L), and a predetermined temperature. It is the figure analyzed about the case where a predetermined flow rate is supplied to. FIG. 14 is a side cross-sectional view when the cleaning gas in the exhaust pipe with the quartz wall attached is supplied.

  For example, when the inside of the exhaust pipe is cleaned with a cleaning gas supply amount of 100 cc as shown in FIG. 13C, the cleaning gas is uniformly supplied to the region I around the flange water cooling portion 701 of the exhaust pipe 230. If the supply amount of the cleaning gas is 500 cc, the cleaning gas can be supplied to almost the entire interior of the exhaust pipe 230 as in the region H of FIG. Further, when the supply amount of the cleaning gas is 1000 cc as shown in FIG. 13A, the cleaning gas can be uniformly supplied to the entire exhaust pipe 230 as in the region G. By providing the quartz wall 1101 in this manner, the cleaning gas ClF 3 can be uniformly supplied to the inner wall surface of the exhaust pipe as shown in FIG. 14, and the by-product generated around the flange water cooling portion 702 can be reliably removed. Is possible.

Here, the inside of the exhaust pipe is cleaned using ClF3 as the cleaning gas. However, the gas for cleaning the inside of the exhaust pipe is not limited to this, and other cleaning gas may be used. The maximum amount and the minimum amount to be supplied may be appropriately changed according to the type of cleaning gas to be supplied. Furthermore, the control of the gas supply amount is not limited to the above-described method, and a constant amount that can uniformly clean the inner surface of the exhaust pipe may be continuously supplied under a certain condition.

Further, although the exhaust pipe described above is described so as to form a flow path that can uniformly supply the cleaning gas using a quartz wall, the material of the wall forming the flow path does not need to be quartz, and is necessary. Any material may be used as long as the conditions can be satisfied. Further, the shape may be formed so as to be integrated with the exhaust pipe.

<Details of gas supplied to each gas supply system>
Next, the first gas supply system and the second gas supply system will be described with reference to FIG. As shown in FIG. 4, the first gas line 222 includes mass flow controllers (hereinafter referred to as MFC) 211a and 211b as flow rate controllers (flow rate control means) for SiH 4 gas, HCl gas, and inert gas. , 211c and valves 212a, 212b, 212c, for example, are connected to an SiH4 gas supply source 210a, an HCl gas supply source 210b, and an inert gas supply source 210c.

With the above configuration, the supply flow rate, concentration, partial pressure, and supply timing of SiH 4 gas, HCl gas, and inert gas can be controlled in the reaction chamber 44. The valves 212a, 212b, and 212c and the MFCs 211a, 211b, and 211c are electrically connected to the gas flow rate control unit 78, and are controlled at a predetermined timing so that the flow rate of the supplied gas becomes a predetermined flow rate. (See FIG. 5). Note that SiH 4 gas, HCl gas, and inert gas supply sources 210 a, 210 b, 210 c, valves 212 a, 212 b, 212 c, MFC 211 a, 211 b, 211 c, first gas line 222, first gas supply nozzle 60 A first gas supply system is configured as a gas supply system by at least one first gas supply port 68 provided in the first gas supply nozzle 60.

Further, the second gas line 260 is connected to the C3H8 gas supply source 210d through the MFC 211d and the valve 212d as a flow rate control unit for C3H8 gas, for example, as C (carbon) atom-containing gas, and as the reducing gas, For example, the H2 gas is connected to the H2 gas supply source 210e via the MFC 211e as a flow rate control means and a valve 212e.

With the above configuration, the supply flow rate, concentration, and partial pressure of C3H8 gas and H2 gas can be controlled in the reaction chamber 44. The valves 212d and 212e and the MFCs 211d and 211e are electrically connected to the gas flow rate control unit 78, and are controlled at a predetermined timing so that the supplied gas flow rate becomes a predetermined flow rate ( (See FIG. 5). Gas supply is provided by gas supply sources 210d and 210e of C3H8 gas and H2 gas, valves 212d and 212e, MFCs 211d and 211e, a second gas line 260, a second gas supply nozzle 70, and a second gas supply port 72. A second gas supply system is configured as the system.

Thus, by supplying the Si atom-containing gas and the C atom-containing gas from different gas supply nozzles, it is possible to prevent the SiC film from being deposited in the gas supply nozzle. In addition, what is necessary is just to supply appropriate carrier gas, respectively, when adjusting the density | concentration and flow velocity of Si atom containing gas and C atom containing gas.

Furthermore, a reducing gas such as hydrogen gas may be used in order to use the Si atom-containing gas more efficiently. In this case, it is desirable to supply the reducing gas through the second gas supply nozzle 70 that supplies the C atom-containing gas. In this way, the reducing gas is supplied together with the C atom-containing gas and mixed with the Si atom-containing gas in the reaction chamber 44, so that the reducing gas is reduced. Therefore, the decomposition of the Si atom-containing gas is compared with that during film formation. Therefore, the deposition of the Si film in the first gas supply nozzle can be suppressed. In this case, the reducing gas can be used as a carrier gas for the C atom-containing gas. Note that the use of an inert gas (particularly a rare gas) such as argon (Ar) as the carrier of the Si atom-containing gas can suppress the deposition of the Si film.

Further, it is desirable to supply a chlorine atom-containing gas such as HCl to the first gas supply nozzle 60. In this way, even if the Si atom-containing gas is decomposed by heat and can be deposited in the first gas supply nozzle, it becomes possible to enter the etching mode with chlorine, and the first gas supply nozzle It is possible to further suppress the deposition of the Si film inside. Further, the chlorine atom-containing gas also has an effect of etching the deposited film, and the first gas supply port 68 can be prevented from being blocked.

In addition, although HCl gas was illustrated as Cl (chlorine) atom containing gas flowed when forming a SiC epitaxial film, you may use chlorine gas.

In the above description, when the SiC epitaxial film is formed, a Si (silicon) atom-containing gas and a Cl (chlorine) atom-containing gas are supplied. However, a gas containing Si atoms and Cl atoms, for example, tetrachlorosilane (hereinafter referred to as SiCl4 and Gas), trichlorosilane (hereinafter referred to as SiHCl3) gas, and dichlorosilane (hereinafter referred to as SiH2Cl2) gas may be supplied. Needless to say, the gas containing Si atoms and Cl atoms is also a Si atom-containing gas or a mixed gas of Si atom-containing gas and Cl atom-containing gas. In particular, SiCl4 is desirable from the viewpoint of suppressing the consumption of Si in the nozzle because the temperature at which it is thermally decomposed is relatively high. Furthermore, when SiCl4 is used, a doping gas (for example, HCl gas (or Cl gas)) is used instead of HCl gas (or Cl gas). N2 gas) may be supplied.

Moreover, although C3H8 gas was illustrated as C (carbon) atom containing gas in the above-mentioned, you may use ethylene (henceforth C2H4) gas and acetylene (henceforth C2H2) gas.

Moreover, although H2 gas was illustrated as reducing gas, it is not restricted to this, You may use other H (hydrogen) atom containing gas. Furthermore, as the carrier gas, at least one of rare gases such as Ar (argon) gas, He (helium) gas, Ne (neon) gas, Kr (krypton) gas, and Xe (xenon) gas may be used. Alternatively, a mixed gas in which the above gases are combined may be used.

<Processing furnace peripheral configuration>
Next, referring to FIG. 6, the configuration of the processing furnace 40 and its surroundings will be described. Below the processing furnace 40, a seal cap 102 is provided as a furnace port lid for hermetically closing the lower end opening of the processing furnace 40. The seal cap 102 is made of a metal such as stainless steel and is formed in a disk shape. An O-ring (not shown) is provided on the upper surface of the seal cap 102 as a sealing material that comes into contact with the lower end of the processing furnace 40. The seal cap 102 is provided with a rotation mechanism 104, and the rotation shaft 106 of the rotation mechanism 104 is connected to the boat 30 through the seal cap 102, and the wafer 14 is rotated by rotating the boat 30. It is configured.

Further, the seal cap 102 is configured as a lifting mechanism provided outside the processing furnace 40 so as to be vertically lifted by a lifting motor 122 described later. It is possible to carry in and out. A drive control unit 108 is electrically connected to the rotation mechanism 104 and the lifting motor 122, and is configured to control at a predetermined timing so as to perform a predetermined operation (see FIG. 5).

A lower substrate 112 is provided on the outer surface of the load lock chamber 110 as a spare chamber. The lower substrate 112 is provided with a guide shaft 116 that is slidably fitted to the lifting platform 114 and a ball screw 118 that is screwed to the lifting platform 114. Further, an upper substrate 120 is provided at the upper ends of the guide shaft 116 and the ball screw 118 erected on the lower substrate 112. The ball screw 118 is rotated by an elevating motor 122 provided on the upper substrate 120, and the elevating platform 114 is moved up and down by rotating the ball screw 118.

A hollow elevating shaft 124 is vertically suspended from the elevating platform 114, and a connecting portion between the elevating platform 114 and the elevating shaft 124 is airtight. The elevating shaft 124 is moved up and down together with the elevating platform 114. The elevating shaft 124 passes through the top plate 126 of the load lock chamber 110, and a sufficient clearance is formed in the through hole of the top plate 126 through which the elevating shaft 124 passes so that the elevating shaft 124 does not contact the top plate 126. Has been.

Further, a bellows 128 is provided as a hollow elastic body having elasticity so as to cover the periphery of the lifting shaft 124 between the load lock chamber 110 and the lifting platform 114, and the load lock chamber 110 is hermetically sealed by the bellows 128. It is supposed to be kept. The bellows 128 has a sufficient amount of expansion and contraction that can accommodate the amount of elevation of the lifting platform 114, and the inner diameter of the bellows 128 is sufficiently larger than the outer diameter of the lifting shaft 124. It is comprised so that 124 may not contact.

The elevating board 130 is horizontally fixed to the lower end of the elevating shaft 124, and the drive unit cover 132 is airtightly attached to the lower surface of the elevating board 130 via a seal member such as an O-ring. The elevating board 130 and the drive unit cover 132 constitute a drive unit storage case 134, and this configuration isolates the inside of the drive unit storage case 134 from the atmosphere in the load lock chamber 110.

Further, the rotation mechanism 104 of the boat 30 is provided inside the drive unit storage case 134, and the periphery of the rotation mechanism 104 is cooled by a cooling mechanism 135.

The power cable 138 passes through the hollow portion from the upper end of the elevating shaft 124 and is guided to the rotation mechanism 104 and connected thereto. A cooling water flow path 140 is formed in the cooling mechanism 135 and the seal cap 102. Further, a cooling water pipe 142 is led from the upper end of the elevating shaft 124 through the hollow portion to the cooling water flow path 140 and connected thereto.

As the elevating motor 122 is driven and the ball screw 118 rotates, the drive unit storage case 134 is raised and lowered via the elevating platform 114 and the elevating shaft 124.

When the drive unit storage case 134 is raised, the seal cap 102 provided in an airtight manner on the elevating substrate 130 closes the furnace port 144 that is an opening of the processing furnace 40, so that wafer processing is possible. Further, when the drive unit storage case 134 is lowered, the boat 30 is lowered together with the seal cap 102, and the wafer 14 can be carried out to the outside.

<Control unit>
Next, referring to FIG. 5, the control configuration of each part constituting the semiconductor manufacturing apparatus 10 for forming a SiC epitaxial film will be described.

The temperature control unit 52, the gas flow rate control unit 78, the pressure control unit 98, and the drive control unit 108 constitute an operation unit and an input / output unit, and are electrically connected to a main control unit 150 that controls the entire semiconductor manufacturing apparatus 10. ing. The temperature control unit 52, the gas flow rate control unit 78, the pressure control unit 98, and the drive control unit 108 are configured as a controller 152.

<Method of forming SiC film>
Next, as a step of the semiconductor device manufacturing process using the semiconductor manufacturing apparatus 10 described above, a substrate manufacturing method for forming, for example, a SiC film on a substrate such as a wafer 14 made of SiC or the like will be described. In the following description, the operation of each part constituting the semiconductor manufacturing apparatus 10 is controlled by the controller 152.

First, when the pod 16 storing a plurality of wafers 14 is set on the pod stage 18, the pod 16 is transferred from the pod stage 18 to the pod storage shelf 22 by the pod transfer device 20 and stocked. Next, the pod 16 stocked on the pod storage shelf 22 is transported and set to the pod opener 24 by the pod transport device 20, the lid of the pod 16 is opened by the pod opener 24, and the pod 16 is detected by the substrate number detector 26. The number of wafers 14 housed in is detected.

Next, the wafer 14 is taken out from the pod 16 at the position of the pod opener 24 by the substrate transfer device 28 and transferred to the boat 30.

When a plurality of wafers 14 are loaded into the boat 30, the boat 30 holding the wafers 14 is loaded into the reaction chamber 44 (boat loading) by the lifting and lowering operation of the lifting platform 114 and the lifting shaft 124 by the lifting motor 122. . In this state, the seal cap 102 is in a state of sealing the lower end of the manifold 36 via an O-ring (not shown).

After the boat 30 is loaded, the reaction chamber 44 is evacuated by the evacuation device 220 so that the inside of the reaction chamber 44 has a predetermined pressure (degree of vacuum). At this time, the pressure in the reaction chamber 44 is measured by a pressure sensor (not shown), and the APC valve 214 communicating with the first gas exhaust port 90 and the second gas exhaust port 390 based on the measured pressure is used. Feedback controlled. Further, the derivative 48 is heated so that the inside of the wafer 14 and the reaction chamber 44 has a predetermined temperature. At this time, the current supply to the induction coil 50 is feedback controlled based on temperature information detected by a temperature sensor (not shown) so that the reaction chamber 44 has a predetermined temperature distribution. Subsequently, when the boat 30 is rotated by the rotation mechanism 104, the wafer 14 is rotated in the circumferential direction.

Subsequently, Si (silicon) atom-containing gas and Cl (chlorine) atom-containing gas contributing to the SiC epitaxial growth reaction are supplied from gas supply sources 210a and 210b, respectively, and the reaction chamber 44 is supplied from the first gas supply port 68. Erupted inside. Further, after the opening degrees of the corresponding MFCs 211d and 211e are adjusted so that the C (carbon) atom-containing gas and the reducing gas H2 gas have a predetermined flow rate, the valves 212d and 212e are opened, The gas flows through the second gas line 260, flows through the second gas supply nozzle 70, and is introduced into the reaction chamber 44 through the second gas supply port 72.

The gas supplied from the first gas supply port 68 and the second gas supply port 72 passes through the inside of the derivative 48 in the reaction chamber 44 and passes through the gas exhaust pipe 230 from the first gas exhaust port 90. Exhausted. When the gas supplied from the first gas supply port 68 and the second gas supply port 72 passes through the reaction chamber 44, the gas contacts the wafer 14 made of SiC or the like, and the SiC is formed on the surface of the wafer 14. Epitaxial film growth is performed. Here, the film forming gas supplied from the two first gas supply nozzles 60 is ejected in a direction in which the ejection directions intersect. Further, the film forming gas supplied from the three second gas supply nozzles 70 is ejected in a direction in which the ejection directions intersect. Furthermore, the point where the film forming gas supplied from the first gas supply nozzle 60 intersects is supplied so as to be farther from the point where the film forming gas supplied from the second gas supply nozzle 70 intersects. This makes it possible to make the concentration distribution in the wafer 14 surface uniform.

Further, after the opening degree of the corresponding MFC 211f is adjusted by the gas supply source 210f so that the Ar gas, which is a rare gas as an inert gas, has a predetermined flow rate, the valve 212f is opened, and the third gas line 240 is supplied to the reaction chamber 44 from the third gas supply port 360. Ar gas which is a rare gas as an inert gas supplied from the third gas supply port 360 passes between the heat insulating material 54 in the reaction chamber 44 and the reaction tube 42, and the second gas exhaust port 390. Exhausted from.

Although the present invention has been described with reference to the drawings, various modifications can be made without departing from the spirit of the present invention.

As mentioned above, although this invention has been demonstrated along embodiment, the main aspect of this invention is added here.
(Appendix 1)
A boat loading process for carrying a plurality of substrates into the reaction chamber while being held in the boat;
A gas supply step of supplying a gas to the substrate;
An exhaust process for exhausting the gas supplied by the gas supply process from an exhaust pipe;
A substrate processing method, a semiconductor device manufacturing method, and a substrate manufacturing method, comprising: a cleaning gas supply step of supplying a cleaning gas to a cleaning gas flow path in the exhaust pipe in order to clean the inside of the exhaust pipe.
(Appendix 2)
A processing chamber for processing a plurality of substrates;
A boat placed in the reaction chamber in a state of holding the plurality of substrates;
A gas supply unit installed in the reaction chamber for supplying a gas for processing the plurality of substrates;
An exhaust unit for exhausting the gas supplied into the reaction chamber by the gas supply unit;
The substrate processing apparatus, wherein the exhaust unit includes a cleaning gas supply unit that supplies a gas for cleaning the inside of the exhaust unit, and a cleaning gas passage that allows the cleaning gas to flow into the exhaust unit.
(Appendix 3)
In Supplementary Note 2, the cleaning gas flow path is formed by a quartz wall provided in the exhaust section.
(Appendix 3)
A boat loading process for carrying a plurality of substrates into the reaction chamber while being held in the boat;
A gas supply step of supplying a gas to the substrate;
An exhaust process for exhausting the gas supplied by the gas supply process from an exhaust pipe having a short pipe nozzle inside;
A substrate processing method, a semiconductor device manufacturing method, and a substrate manufacturing method, each including a cleaning gas supply step for supplying a cleaning gas to clean the inside of the exhaust pipe.
(Appendix 4)
A processing chamber for processing a plurality of substrates;
A boat placed in the reaction chamber in a state of holding the plurality of substrates;
A gas supply unit installed in the reaction chamber for supplying a gas for processing the plurality of substrates;
An exhaust part for exhausting the gas supplied into the reaction chamber by the gas supply part through an exhaust pipe;
A cleaning gas supply unit for supplying a gas for cleaning the inside of the exhaust unit;
A substrate processing apparatus having a short tube nozzle for ejecting the cleaning gas in a plurality of directions on the exhaust pipe side of the cleaning gas supply unit.

DESCRIPTION OF SYMBOLS 10: Semiconductor manufacturing apparatus, 12: Housing | casing, 14: Wafer, 15: Wafer holder, 15a: Upper wafer holder, 15b: Lower wafer holder, 16: Pod, 18: Pod stage, 20: Pod conveyance apparatus, 22: Pod Storage shelf, 24: Pod opener, 26: Substrate number detector, 28: Substrate transfer machine, 30: Boat, 32: Arm, 34A: Boat heat insulation part, 34B: First heat exchange part, 34C: Second heat exchange Part: 36: manifold, 40: processing furnace, 42: reaction tube, 44: reaction chamber, 48: derivative, 50: induction coil, 52: temperature controller, 54: heat insulating material, 55: outer heat insulating wall, 58: Magnetic seal, 60: first gas supply nozzle, 68: first gas supply port, 70: second gas supply nozzle, 72: second gas supply port 72, 78: gas flow rate controller, 90: first 1 Gas exhaust port, 98: pressure control unit, 102: seal cap, 104: rotation mechanism, 106: rotation shaft, 108: drive control unit, 110: load lock chamber, 112: lower substrate, 114: lifting platform, 116: guide Shaft, 118: Ball screw, 120: Upper substrate, 122: Lifting motor, 124: Lifting shaft, 128: Bellows, 130: Lifting substrate, 132: Drive unit cover, 134: Drive unit storage case, 135: Cooling mechanism, 138 : Power cable, 140: Cooling water flow path, 142: Cooling water piping, 150: Main control unit, 152: Controller, 200: Gas supply unit, 210: Gas supply source, 211: MFC, 212: Valve, 214: APC valve 222: first gas line 230: gas exhaust pipe 260: second gas line 300: structure 360 The third gas supply port, 390: second gas outlet, 701: cleaning gas supply unit, 702: flange water-cooling unit, 901: short pipe nozzle, 1101: quartz walls.

Claims (3)

A boat loading process for carrying a plurality of substrates into the reaction chamber while being held in the boat;
A gas supply step of supplying a gas to the substrate;
An exhaust process for exhausting the gas supplied by the gas supply process from an exhaust pipe;
A substrate processing method comprising: a cleaning gas supply step of supplying a cleaning gas to a cleaning gas flow path in the exhaust pipe in order to clean the inside of the exhaust pipe.
A boat loading process for carrying a plurality of substrates into the reaction chamber while being held in the boat;
A gas supply step of supplying a gas to the substrate;
An exhaust process for exhausting the gas supplied by the gas supply process from an exhaust pipe;
A method for manufacturing a semiconductor device, comprising: a cleaning gas supply step for supplying a cleaning gas to a cleaning gas flow path in the exhaust pipe in order to clean the inside of the exhaust pipe.
A processing chamber for processing a plurality of substrates;
A boat placed in the reaction chamber in a state of holding the plurality of substrates;
A gas supply unit installed in the reaction chamber for supplying a gas for processing the plurality of substrates;
An exhaust unit for exhausting the gas supplied into the reaction chamber by the gas supply unit through an exhaust pipe;
The substrate processing apparatus, wherein the exhaust unit includes a cleaning gas supply unit that supplies a gas for cleaning the inside of the exhaust unit, and a cleaning gas passage that allows the cleaning gas to flow into the exhaust unit.